The TIA/EIA (Telecommunications Industry Association/Electronic Industries Association) IS-2001, or IOS (3GPP2 A.S0001 Inter Operability Specification), standard provides a compatability standard for cellular mobile telecommunications systems that operate as a cdma2000, 1XEV-DO, 1XEV-DV, or any other technology supported by an A.S0001/IS-2001 based Access Network. The standard ensures that a mobile station (MS) operating in a cdma2000 system can obtain communication services when operating in a cellular communication system or personal communication system (PCS) manufactured according to the standard. To ensure compatibility, radio system parameters and call processing procedures are specified by the standard, including call processing steps that are executed by an MS and a base station serving the MS in order to establish a call and digital control messages and analog signals that are exchanged between elements of an infrastructure that includes the base station.
A typical cdma2000 communication system infrastructure includes a base station in communication with a Packet Control Function (PCF). An interface between the base station and the PCF includes an A9 interface that provides a signaling interface between the base station and the PCF and an A8 interface that provides a bearer path between the base station and the PCF. These interfaces are collectively known in the IS-2001, or IOS, standard as the Aquinter reference point or A8/A9 interface.
The evolution of the IOS standard has resulted in the existence of multiple versions of the standard. As the standard has evolved, later versions of the standard support functions and provide signaling that is not included in earlier versions of the standard. A possible outcome of the co-existence of multiple versions of the standard is that a base station and a PCF that are communicating over the A8/A9 interface may each conform to a different version of the IOS standard. The entity running software conforming to the higher level version of the standard may then expect the entity running software conforming to the lower level version of the standard to support functions that the latter entity is not capable of supporting. The possible results include miscommunication between the two entities, wasted communication resources as one entity awaits responses that are not forthcoming or communicates with applications that are not supported by the other entity, and dropped telephone calls.
Furthermore, if a disruptive event occurs at either the base station or the PCF as a result of a hardware or a software failure, resulting in an entity reset, the resources allocated for supporting packet data communications remain allocated. For example, if a PCF resets, air interface traffic channel resources at base stations associated with the resetting PCF remain allocated by the base stations even though the communications supported by the packet data resources are terminated. Again this results in wasted communication resources.
Therefore a need exists for a method and an apparatus for allowing software version information to be exchanged between a base station and a PCF and for facilitating a release of communication resources in the event of a failure at either the base station or the PCF.